Proto X

iTrader: (42)

Working on my cousins 98 ta
When the car is cold(before o2s come into play) it runs great
When o2s switch bank 2 goes crazy and car wants to die.
I have switched o2s side to side and problem stays on bank 2
What all could this be?

sweet-94z28

iTrader: (30)

Might be a short in the wiring somewhere. Check all of the wires from the O2 plug back up past the exhaust (to make sure it didn't get burnt). Also, do you have any exhaust leaks? Might be worth looking around the EGR area or AIR injection areas. The last thought would maybe be a bad PCM. If you have another one to swap in or a friend with another 98 car, that may tell a lot. My T/A had a PCM go bad and all kinds of things quit working and acted haywire.

Sunsetmaro

iTrader: (6)

Im assuming you have a scanner? Any mods on the car? Switching o2's sounds like shotgun troubleshooting unless your scanner is telling you that possibly a o2 is bad. I would get it scanned, atleast at autozone or something if you don't have a scanner and go from there. Im dealing with my own issue with my car and unfortunatly im sitting at the p0300 code, random misfire. Waiting for a buddy from a GM dealership to head down and scan my car to see really whats going on....

96LS1zee

Define crazy? Do the LTFT and STFT on bank 2 go high or low? What does bank 1 read? What does the rear o2 read when that happens(if there is one and it has a cat)

Proto X

iTrader: (42)

Stft is fine on both banks. Ltft goes to max value. No cats or rear o2's. bank 1 ltft is normal range.

96LS1zee

Max value positive or negative? what does bank 2 o2 sensor read? Try disconnecting the sensor and seeing if the problem persists

SMOKINV8

iTrader: (6)

Sounds like a huge exhaust leak on bank 2, but you should be able to hear it if that's the cause. If you can't hear it, check wiring as mentioned above. Make sure it's not melted to the header.

Proto X

iTrader: (42)

This is what it's doing at idle.

chernandez240

Proto X, did you ever figured out this problem?

having the same problem here, Bank 2 is showing 13% on the LTFT.